Restrictions necessary for the proper conservancy of the forests are, however, imposed, and the system of shifting cultivation, which denudes a large area of forest growth in order to place a small area under crops, is held to cost more to the community than it is worth, and is only permitted, under due regulation, where forest tribes depend on it for their sustenance.
Above the intakes of the water companies (at Hampton or in the vicinity), the Thames Conservancy has enforced the requirements of parliament that no sewage or other pollution shall be allowed to pass into the Thames, into its tributary streams, or even into any water communicating with them.
Measures of conservancy have been suggested, but their execution would be almost impracticable.
Systematic conservancy of the Indian forests received a great impetus from the passing of the Forest Law in 1878, which gave to the government powers of dealing with private rights in the forests of which the chief proprietary right is vested in the state.
The ports of Hull and Goole have been administratively combined since 1888, the conservancy of the river being under the Humber Conservancy Board.
The Thames Conservancy also offered itself as the public authority.
The Pruth and Sereth are navigable for a short distance by small sailing craft; the conservancy of the Danube (q.v.) is controlled by a European commission, which sits at Galatz.
The first charter by which the city claims the jurisdiction and conservancy of the river Thames was granted by Richard I.
The Famine Commission of 1878 urged the importance of forest conservancy as a safeguard to agriculture, pointing out that a supply of wood for fuel was necessary if cattle manure was to be used to any extent for the fields, and also that forest growth served to retain the moisture in the subsoil.
The administration of the law devolves upon local forest conservancy boards.